1. Field of the Invention
This invention relates to a pelletizing device for plastic material and more particularly to a relatively compact device which prevents breakage of strands of the plastic material.
2. Description of the Prior Art
Conventional granulation of plastic materials has been implemented by extruding many strands of material through dies by an extruder and cutting them by a hot cut system or a cold cut system to make pellets. The conventional device requires more installation cost and is mostly used for pelletizing virgin material. Pelletizing of reclaimed material has usually been effected by a cold cut system.
The cold cut system draws many strands of material (about 2 to 4 mm dia.) being extruded through strand dies of an extruder. The strands are sufficiently cooled by passing through a cooling water tank by way of a drawing roll of a chop cutter, which cuts the strands for granulation. By the above system, strands are apt to be broken by uneven extrusion of the extruder, or disturbance of extrusion balance by the extruder or balance of drawing by the inclusion of foreign materials even when only one of the strands is broken and abandoned. The broken strand solidifies in the cooling water tank and may cause trouble. Consequently, attendance of an operator is always necessary for watching the operation which cannot be unattended contrary to the man-hour saving requirements of modern age. Further, because of the necessity of a long cooling water tank of 2 to 4 meter long, the conventional equipment requires a larger space for installation.